The present invention relates to the construction and the driving device for the liquid crystal display device for camera.
Until now, for use as a display device in the view finder in an optical photographing device such as a camera, the finger of the ampere meter, the LED and so on are made use of. However, the ampere meter has substantial disadvantages in that it is sensitive to mechanical shock, much space is needed for its arrangement and, within the camera, further, strict dust-proofing is needed. On the other hand, when an LED is made use of, regardless of the 7 segment display or the dot system display, it is necessary to use many LED elements the LED power consumption is very substantial and represents a large load for a small battery such as a silver oxide battery used in a camera. Further, the LED is difficult to look at under high brightness, which is inconvenient.
On the other hand, for use as the display device in such view finders as mentioned above, various segment display device employing liquid crystal have so far been proposed. In this case, the power consumption of the liquid crystal display device is remarkably small as compared with that of the LED and the display device itself by means of the liquid crystal is compact and needs little space, which is convenient. On the other hand, in the case of the display device using liquid crystal, as few as only 4 figures can be driven in accordance with the dynamic drive system and, further, the ratio of the effective voltage at the selecting point to that at the non-selecting point is so small that there exists a danger that possibility of the misoperation due to temperature variation should be increased. On the other hand, in the case of the static drive system there is no such weak point as mentioned above, but the wiring is very complicated, which also inconvenient.
Further, especially when the display device employing liquid crystal is used in the view finder for an optical photographing device such as camera, unless it is arranged in line, substantial space could be needed, whereby the 7 segment display is put aside.
Although in this case, the dot system display is most suited for displaying the photographing informations, in order to carry out the dot system display by means of the lined liquid crystal cell in accordance with the conventional method many problems need to be solved.